There are a variety of medical devices that sense data, provide diagnostic information, and/or deliver therapy. When such a device is implanted (in whole or in part), it is referred to as an implantable medical device (IMD). Examples of IMDs are implantable loop recorders, implantable pacemakers, and implantable cardioverter-defibrillators, which are electronic medical devices that monitor the electrical activity of the heart and/or provide electrical stimulation to one or more of the heart chambers, when necessary.
As IMD technology advances in an attempt to address a myriad of life sustaining/enhancing needs, issues such as IMD battery longevity, IMD mass, and increased functionality remain key considerations in the IMD design process. A conventional approach to providing power within an IMD involves the use of a self-contained battery, not unlike a common battery which is commercially available to the consumer. Such a self-contained battery includes active electrochemical cell components housed in a battery can. Battery housing connectors or contacts are provided for establishing electrical connections to circuitry disposed within the IMD.
The functions attributable to the IMD may be impacted by the depletion of the battery energy. For example, each IMD generally includes a processor that executes “operation instructions” or applies “operation code” to carry out the various operational functions of the IMD. Typical operation instructions are stored in one or more non-volatile memory modules in the IMD. In addition, data sensed by the IMD is stored in the one or more volatile memory modules. Non-volatile memory includes, for example, flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and a non-volatile random-access memory (NVRAM).
Much attention has been placed on optimizing the functions of the IMD to optimize consumption of the power source of an implantable medical device. The battery consumption is always a concern when designing implantable medical devices, but this concern is increased for small form factor devices that can only accommodate a small battery canister. There remains a need for increased optimization of the operational functions of the IMD pertaining to the storage operations in the volatile memory modules.